Railway traffic-controlling apparatus



Nov. 15, 1927.

7 1,649,629 H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS 3Sheets-Sheet 1 Original Filed Dec, 21, 1923 INVENTOR Nbv. f5; 1927.1,649,623;

- H. A. WALLACE 1 RAILWAY TRAFFIC CONTROLLING APPARATUS Original FiledDec. 21, 23 s Sheets-Sheet 2 37 F W Z? a I 6 L 3 :4 95 ENE; 4 yy a a @T2 I 92 [a 4 fi'oceedfi, "G Caution rv INVENTOR. A LLWMM Nov. 15, 1927.

H. A. WALLACE RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed Dec.21, 1923 3 Sheets-Sheet 5 J4 J 1 l M I v w -51 42 I 45 45 3'7 j 44 51 W{\(56 a 5.2" 52 L 6 Y Proceecf 55 F- Caazl'onw 5Q sz o mi Prepare :0Acknowledge 1m} roceeded Resirz'ced ASjoeecf;@ Proceed af 510W fijoeeaINVENTOR 1 4 Q, WWW,

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Fatented New. 15, 1927..

HERBERT A. WALLACE, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THEIPQRATION OF PENNSYLVANIA.

0F SWISSVALE, PENNSYLVANIA, A GOR- RAILWAY TRAFFIC-CONTROLLINGAPPARATUS.

v Applicatlonfiled December 21, 1923, Serial No. 681,946. Renewed May 2,1927.

My invention relates to railway trafic controlling apparatus, andparticularly to apparatus of the type comprising governing means carriedon a train and controlled by energy received from the trackway.

it will describe several forms of apparatus embodying my invention, andwill then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing oneform of trackway apparatus embodying my invention. Fig. 2 is a viewpartly diagrammatic, showing one form of train-carried governing meanssuitable for cooperation with the trackway apparatus shown in Fig. 1.Figs. 3 and t are views showing modifications of the train-carriedgoverning means shown in Fig. 2 also embodying my invention.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Fig. 1, the reference characters 1 and l" designatethe track rails of a railway track 21, which rails are divided byinsulated joints 2 into a plurality of sections C-D D-E. E-F, etc.Traffic normally moves along the track 21 from left to right. but insome instances it may move in the opposite direction, as will appearhereinafter,

Located in the section EF is a switch M which governs traffic into abranch track 89, and located in the track 89 is another switch X whichgoverns traffic into a third track 90.

Trafiic moving from left to right along the portion of track 21 shown inthe drawing is governed by signals A A and A located as here shown atthe points C, D and E, re spectively. T rafiic moving from right to leftalong the track 21 is governed by a dwarf signal A located at the pointF, and traffic moving from right to left along tracks 90 and 89, isgoverned by dwarf signals A and A located adjacent the points K and H.

respectively. in these two tracks. The signals A A, A and A togetherwith the switches M and N. are included in an interlocking plant and arecontrolled in the usual and well understood manner The control of thesesignals and switches forms no part of my present invention, and.consequently, is omitted from the drawing to simplify the disclosure.Signals A and A are automatic signals operating in the usual and wellunderstood manner, the. control circuits and apparatus for these signalsbeing, likewise, omitted from the drawing for the reason pointed outabove.

Each track section is provided with means for connecting a source ofalternating track circuit current across the rails adjacent the righthand end of the section. Referring particularly to section CD, thiscurrent is supplied by a transformer 18, the secondary of which isconnected across the rails of the section through a pole-changer P andthe primary of which is constantly supplied with alternating currentfrom the secondary of a transformer L The primary of transfor mer L aswell as of each of the remaining transformers L is constantly suppliedwith alternating currentfrom a suitable source, not shown in thedrawing. Track circuit current is similarly supplied to section DE froma transformer 19, through a polechanger P In section EF the trackcircuit current is supplied from a transformer 16, throughpole-changingcontacts 63 on the relay 65, which relay is controlled by atrack relay X, as hereinafter explained.

Each section is also provided with means for supplying an additionalcurrent to the track rails, which current I will herein term the loopcurrent. For this purpose the sections are provided with resistances 8,9, 10 and 11, connected across the rails, and the loop current circuitsare connected with these resistances in such manner that the loopcurrent flows in the same direction in both track rails at any giveninstant. Considering section 0-D, for example, the secondary oftransformer B is connected with the middle points of resistances 8 and9, respectively. The means for supplying loop current to the remainingportions of the stretch of track shown in the drawing, will be explainedhereinafter. The loop current is of the same frequency as the trackcircuit current, and in the system herein shown these two cur.- rentsare both furnished by the transformers L.

Referring now to Fig. 2. the train-carried mechanism comprises twomagnetizable cores 92 and 92*, mounted in front of the forward axle ofthe locomotive and disposed above and transversclywith respect to thetwo track rails 1 and 1 The cores 92 and 92" are provided with windings24 and 24, respectively, so connected that the voltages-induced thereinby track circuit current in the rails are additive. The locomotive isalso provided with two additional cores 93 and 93 carrying coils 25 and25, respectively, which coils are so connected that the voltages inducedtherein by loop current in the track rails are additive. The circuitincluding the track circuit coils 24 and 24: supplies energy to a statorwinding 34 of an induction motor relay J, whereas the circuit includingthe loop coils 25 and 25 supplies energy to the other stator winding 33of the relay J. As here shown, amplifying devices 26 and 26 areinterposed between the pick-up coils and the relay windings.

The relay J comprises a rotor 35 controlling a plurality of contacts 30,31 and 32. These contacts in turn control any suitable train governingmechanism, which, as here shown, comprises six signal lamps G, Y, it, U,T and S. When relay J is supplied with energy due to track circuitcurrent of normal relative polarity and loop current of normal relativepolarity, the contact fingers occupy their right hand positions, thatis,the positions in which they are shown in the drawing. The proceed lamp Gis then energized by virtue of a circuit which passes from the terminalof a suitable source of current, through the right hand point of contact30 and the proceed lamp G to the terminal of the same source of current.When the relay J is supplied with energy due to track circuit current ofreverse relative polarity and loop current of normal relative polarity,the contact fingers are swung to the left, whereupon the proceed lamp(1' is extinguished, and the caution lamp Y is lighted due to a circuitwhich includes the left hand point of contact 30, and which circuit willbe obvious from the drawing. When the supply ofeither track circuitcurrent or loop current 18 discontinued, the contact fingers of relay Joccupy vertical or intermediate positions, so that the stop lamp R islighted by virtue of a circuit which includes the middle point ofcontact 30.

When the train-carried mechanism is supplied with track circuit currentof normal relative polarity and with loop current of normal relativepolarity but intermittently interrupted, it will be seen that thecontacts of relay J will oscillate from their right hand points to theirintermediate points. Under this condition two slow-acting relays W and Xwill become closed in the following manner: When the contacts of relay Joccupy their intermediate positions, relay W will be energized throughcontact 32 by virtue of a circuit which will be obvious from thedrawing. As the contacts of relay J swing to the right, relay X willbecome energized through a circuit which passes from the terminal of asuitable source of current, through contact 36 of relay W, righthandpoint of contact 31 of relay J, and the winding of I'GlBW X. to theterminal of the same source of current. The slow-acting characteristicsof relays W and X are such that these relays remain closed as long asthe contacts of relay J continue to oscillate in the manner described. Acircuit is then closed which passes from terminal, through contact 36 ofrelay W, contact 37 of relay X, back point of contact 39 of relay Q, andlamp U to the terminal. Lamp U, when lighted, indicates Prepare toacknowledge.

When the train-carried mechanism is subjected to track circuit currentof reverse relative polarity and loop current of normal relativepolarity but intermittently interill) W, contact 38 of relay Q, and lampT to the terminal of the source of current. Lamp T, when lighted,indicates Proceed at restricted speed. When the train-carried mechanismis subjected to track circuit current of reverse relative polarity andto loop current of alternately normal and reverse relative polarity, itwill be apparent that relay J will be alternately energized in normaland reverse directions, so that the contact lingers will swing fromtheir right hand to their left hand positions and back continuously.When relay J is operated in this manner relay W will, of course, beenergized each time that contact finger 32 passes through itsintermediate position. Each time that contact finger 31 occupies itsright hand position, relay X will be energized, and each time thatcontact finger 31 occupies its left hand position, relay Q, will beenergized. The slow-acting characteristics of these rclays are such thatunder the conditions specified, all three relays remain closed. Acircuit for lamp S is then closed, which circuit passes from theterminal of a source of current, through contact 36 of relay ll. coutact37 of relay X, front point of contact 39 of relay Q, and lamp S to theterminal of thesame source of current. Lamp 55, when lighted, indicatesProceed at slow speed. ltwill, of course, be noted that duringintermittent operation of relay J, one or more of the lamps G, Y and Rwill he inter- I mittently lighted. This can be avoided, if desired, bysuitable means, such, for example, as slow-acting relays interposedbetween contact 30 or" relay J and the lamps G, Y and lit.

On the other hand, relays W, K and Q reaaeae and lamps U, T and S couldbe omitted, and the indications given by these lamps could be given bylamps G, Y and R. With this modification the Prepare to acknowledgeindication would be given by the alternate lighting of lamps G and R,the Proceed at restricted speed indication would be given by alternatelighting of lamps Y and G, and the Proceed at slow speed indicationwould be given by successively lighting all three of lamps in the orderG, ll, Y. R, G. R, etc.

Referring again to Fig. 1, the intermittent interruption of the loopcurrent is accomplished by circuit controllers Z Z? and Z".

e In the form here shown, each of these controllers comprises a magnet94 and a plurality of contacts controlled thereby. including one contact47 which is in series with the magnet 94 to cause intermittent operationof the contacts when current is supplied to the magnet. Operativelyconnected with the contacts is a pendulum 24, one purpose of which is toprovide the desired periodicity or" contact operation. This pendulum isso adjusted that the time interval during which the loop current isinterrupted is less than the time interval of any one of the slowactingrelays W, X and Q in Fig. 2, so that when a circuit controller Z isoperating and the train-carried mechanism is under the influence of thelocal current controlled by such circuit controller, these slow-actingrelays remain closed.

In the following discussion I will assume that the track circuit currentis of normal relative polarity when the rail at the left hand side of atrain is connected with the terminal of the associated track transformerwhich is marked with a sign in the drawing. For example, in section CD,the track circuit current is of normal relative polarity when the lowerterminal of the secondary ot' transformer 18 is connected with the uppertrack rail 1. I will also assume that the loop current is of normalrelative polarity when the terminal of the secondary of the associatedtransformer B is connected with the rear of the two resistancesassociated with such secondary. For example, in section CD the loopcurrent is of normal relative polarity when the terminal of transformerB marked with a sign is connected with resistance 10, thisincidentallyi-being the only polarity of the loop current in sectionG-D.

The operation of the apparatus, is as follows:

it will assume that the upper arm of signal A is in its verticalposition, indicating that switch M is in normal position and that themain track 21 is unoccupied for a given distance in advance of thesignal. Signal A then gives what is called a proceed indication.Circuitcontroller Z is at rest, because the circuit for its magnet 94 isnot closed at any one of the governing contacts'58, 59 or 60. The upperarm 3 of signal A will also be in the vertical position, so that circuitcontroller Z will be at rest, because its operating circuit is open atcontact 48. Track circuit current of normal relative polarity will thenbe supplied to section CD, and loop current of normal relative polaritywill, of course-,be supplied to this section between resistances 8 and9.

'Loop current of normal relative polarity will also be supplied to thissection between resistances and 11, because this loop circuit is closedat contact 46 on circuit controller Z and also at contact 49 on signalA. It follows that a train moving toward the right will receive aproceed indication throughout section C-D. In section D-E, track circuitcurrent of normal relative polarity is supplied to the rails becausepolechanger P is shifted to the normal position due to the operation ofarm 5 of signal AP. The circuit for the loop current between resistances8 and 9 is from the terminal of secondary 950i transformer B throughresistance 8, the track rails, resistance 9, and contact 52 to secondary95. Between resistances 10 and 11 the loop circuit passes from secondary96 of transformer B through contact 50, resistance 10, the two rails inmultiple. resistance 11, circuit controller 55, and contact 51 tosecondary 96. It follows, therefore, that a train moving toward theright will receive a proceed indication throughout section D-E.

The operation of the apparatus to the right of point D will be explainedhereinafter.

I will now assume that switch M isin the normal position, but that thesection to the right of point F is occupied so that the upper arm 5 ofsignal A is in its inclined or position. indicating caution. Circuitcontroller Z will then be in operation because its circuit will beclosed at contact operated by signal arm 5. Signal A will still indicateproceed, however, that is, its upper arm 3 will be in the verticalposition, so that circuit controller Z will be at rest. The condition ofthe train governing'circuits in section C-D will then be the same asbefore. In section D-E, the track circuit current is of normal relativepolarity, and the loop current between resistances 8 and 9 is also ofnormal relative polarity because the circuit for secondary 95 is closedat contact 57 operated by arm 6 of signal A Between resistances 10 and11 the loop current is of normal relative polarity but is intermittentlyinterrupted, the circuit for this portion of track being from terminalof secondary 96, through contact 50, resistance 10, resistance 11.contact 55 and contact 51 to secondary 96. This circuit is closed whencontacts 50 and 51 are'in their left hand positween the resistances and11 the indication received on this train will be Prepare to acknowledge.That is to say, relays W and X in Fig. 2 will be closed so that lamp Uwill be lighted.

I will now assume that switch M is reversed and that the middle arm 6 ofsignal A is in the vertical position, so that this signal indicatesProceed at restricted speed. Circuit controller Z will then be inoperation because its circuit is closed at contact 59. In signal A theupper arm 3 will be in the inclined or 45 position and the lower arm 4will be in the vertical position, but the lower arm does not exerciseany control over the train-governing circuits in the present instances.Circuit controller Z will be in operation because of the 45 position ofarm 3, so that loop current of normal relative polarity butintermittently interrupted is supplied to section CD between resistances10 and 11. The track circuit current supplied to this section is ofnormal relative polarity, so that a train moving toward the right willreceive a proceed indication between resistances 8 and 9 but betweenresistances 10 and 11 the indication will be Prepare to acknowledge. Insection D--E the track circuit current will be of reverse relativepolarity because arm 5 of signal A is in the horizontal or zeroposition. The loop current circuit between v resistances 8 and 9 nowpasses from the terminal of secondary 95, through resistance 8,resistance 9 and contact 52 to secondary 95, it being noted that thebranch around contact 52 and including contact 57 is now open becausearm 6 is no longer in the horizontal or zero position; It follows thatthe loop current between resistances 8 and 9 is of normal relativepolarity intermittently interrupted. Between resistances l0 and 11 theloop circuit passes from secondary 96, through contact 50, resistance10, resistance 11, circuit controller 54 and contact 51 to secondary 96,so' that this current is likewise of normal relative polarityintermittently interrupted. A train moving toward the right in sectionDE will, therefore, receive track circuit current of reverse relativepolarity and loop current of normal relative polarity but intermittentlyinterrupted, so that relays W and Q (see Fig. 2)

will be energized, thereby causing lamp T to be lighted, so that theindication given aboard the train is Proceed at restricted speed.

If the middle'arm 6 of signal A is in the inclined or 45 position,indicating that switch M is reversed, and that either track 89 or 90 isoccupied, the indications given to a train in sections CD and D-E willbe the same as when arm 6 is in the vertical position. That is to say,the "positions of the arms of signal A will be the same as before, andin section D--E the loop currents will be the same as before becausecontacts 54 and 59 are both closed in the inclined as well as thevertical positions of arm'fi.

I will now assume that the lower arm 7 of signal A is in the inclined or45 position, so that the signal gives the lowest speed indication ofwhich it is capable. Circuit controller Z will be in operation becauseits circuit is closed at contact 58, circuit controller Z will still bein operation because its circuit is closed at contact 48, it beingunderstood that arm 3 of signal A is'still in the inclined or 45position. The indication given to a train between'resistances 10 and 11in section CD is, therefore, as before Prepare to, acknowledge. Insection DE the track circuit current is of reverse relative polarity andthe loop current between resistances 8 and 9 is of normal relativepolarity intermittently interrupted at contact 52. When a train isbetween resistances 8 and 9, therefore, relays W and Q are closed, sothat the indication given aboard the train is Proceed at restrictedspeed. Between resistances 10 and 11 in section D-E, the relativepolarity of the loop current is periodically reversed; that is, when thecontacts of circuit controller Z .are in the positions shown in thedrawing,

the loop circuit is from secondary 96, through contact 50, resistances10 and 11, contact 53, and contact 51 to secondary 96. When the contactsof circuit controller Z are reversed, the circuit passes from secondary96, through contact 50, contact 53, resistances 11 and 10, and contact56, and contact 51 to secondary 96. The condition between resistances l0and 11, therefore, is track circuit current of reverse-relative polarityand loop current intermittently reversed 1n relative polarity, so thatrelays W, X and Q on the train are all energized, lamp S is lighted, andso the indication given aboard the train is Proceed at slow speed.

Assuming that all three arms of signal A are in horizontal or zeropositions, circuit controlled Z will be at rest, because its opaeaaeaesistances and 11 because of the absence of loop current. Signal A isstill at caution, so that the indication received aboard the trainbetween resistances 10 and 11 in section (3-D will still be Prepare toacknowledge.

The supply of track circuit current to section E-F is controlled by arelay 65, which in turn is governed by a track relay X associated withthe section to the right of point F. Relay X is provided with onewinding 91 which is constantly supplied with alternating current fromthe Secondary of transformer L and with a second winding 99 which isnormally connected across the rails of the section to the right of Fthrough a contact 74 which is closed when signal A is in the horizontalposition. When the section to the right of point F is supplied withtrack circuit current of normal relative polarity, relay X is energizedin such direction that its contact 7 3 is closed, so that relay 65 isthen energized through a circuit which will be obvious from the drawing.When the section to the right of point it is supplied with track circuitcurrent of reverse relative polarity, contact 73 of relay X ,is open,and this contact is also open when the section is occupied by a car ortrain, in either of which cases relay 65 is, of course, de-energized.Assuming that switch M is in the normal position, and that relay 65 isenergized, track circuit'current of normal relative polarity is suppliedto the rails of section E]F through contacts 63 of relay 65 and contacts64 which are operated by switch M and are closed only when switch M isin the normal position. When relay 65 is deenergized, track circuitcurrent of reverse relative polarity is supplied to section lE-F, due tothe fact that the contacts63 of relay 65 constitute a pole-changer.

Loop current is supplied to section Til-F from a transformer 15, theprimary of which 7 is constantly connected with the secondary of,transformer L The circuit for the secondary of transformer is from theterminal through resistance 8 and the rails of section lE-lF inmultiple, wires 97 in mul-.

'tiple, contacts 6% in multiple, contacts 63 in multiple, resistance 11,and contact 7 0 on switch N, to the secondary of transformer 15.

llt will be seen from the foregoin that section EF is constantlysupplied with loop current of normal relative polarity. It follows thatwhen relay is energized a train movingtoward the right will receive aproceed indication throughout this section, whereas when relay 65 isde-energized a train moving toward the right will receive a cautionindication throughout the section, because in the former instance theterminal of transformer 16 is connected with the upper rail 1, and inthe latter instance thfI terminal is connected with the lower ra' 1".

ll will'now assume that switch M is reversed, thereby opening contacts64 and closing contacts 66. The supply oftrack circuit current to, therails at the right-hand end of section E-F is then discontinued, buttrack circuit current is now supplied from the, secondary of transformer16, through contacts 66, and wires 98 to the rails of track 90 at theleft-hand side of point K. Loop current is now supplied from resistance8 at point E to resistance 11, which is in eflect connected across therails of track 90 at the left-hand side of point K, so that if switch Nis set for traflic into track 90, a train moving toward the right willreceive a caution indication from point E to point K, it being notedthat the terminal of transformer 16 is connected with the lower rail oftrack 90.

The signals A A and A, govern trafiic moving from right to left, and allthree of these signals normally indicate stop, that is, they arenormally in the horizontal or zero positions. Signal A is controlled bya manually operable contact 20 and also by a contact 67 operated byswitch M. When switch M is in normal position, contact 67 is closed, sothat signal A may then be moved to the inclined or proceed position byvirtue of a circuit which will be obvious from the drawing. When switchM is in the reverse position. contact 67 is open, so that signal A isheld in the stop position, but

contact 68 is then closed. If switch N is in the normal position, sothat trafiic may move from track 90 into track 89, contact 71 is closed,so that signal A ma then be cleared by closing contact 20. I switch N isin the reverse-position, contact 71 is open and contact 72 is closed, sothat signal A m'ay then be cleared by closing circuit controller 20.When switch M is in normal position the loop circuit for section ElF 1sclosed at contact 69. en switch M is in the reverse osition and switch Nis normal, the loop circuit for section lE-K is closed at contactoperated by switch N. on both switches M and N are reversed, the loopcircuit is open at both contacts 69 and 70, so that no loop current issupplied to the rails between points E and --F or points E and K.

The section to the right of point F in track 21 is supplied with loopcurrent through a circuit which passes from the terminal of secondary100 on transformer B through rcontact 76; resistance 8, the track railsbetween resistances 8 and 9, then through resistance 9 and contact 77 tothe terminal of secondary 100. It follows that when contacts 76 and 77are closed in the positions shown in the drawing, that is, when signal Aindicates stop, loop current of normal relative polarity is supplied tothe rails between points 8 and 9. Track cirk r versed and switch cuitcurrent is supplied to these track rails at a point to the right ofresistance 9, so that a train moving toward the right Wlll receive aproceed or a caution indication accordin as the track circuit current isof norma or reverse relative polarity. In a similar manner, the sectionto the right of point K in track 90 is supplied wlth loopcurrent by acircuit which passes from the terminal of secondary 101 on transformerB, through contact 81, resistance 8, the rails of track 22, ,resistance9. and contact 82 to the terminal of secondary 101. This circuit. isclosed when contacts 81 and 82 arein the positions shown in the drawing,that is, when signal A is at stop, and under this condition loop currentof normal relative polarity is supplied to the rails. Track circuitcurrent is supplied to the rails of this section at a point to the rightof the portion of the section shown in the drawing.

I will now assume that switch M is in normal position, and that signal Ahas been moved to the proceed position to permit a train moving towardthe left to pass'through track 21. The reversal of contact 74 opensthecircuit for track winding 99 of relay X, so that this relay becomesde-energized, thus causing relay to likewise become de-energized. Trackcircuit current is now supplied to the rails of track "21 immediately tothe right of point F the circuit being from the secondary of transformer16, through contacts 63 of relay 65, contacts 64 on switch M andcontacts 74 and 75, which are now reversed, to the rails of track 21.Contacts 76 and 7 7 are now reversed, so that the supply of loop currentfrom secondary 100 of transformer B is'discontinued. Circuit controllerZ is set into operation because the operating circuit for its magnet 94is closed at contact 78 which is now reversed. Loop current is nowsupplied to the rails of track 21 from the secondary of transformer Bthrough contact 61, contact 76, resistance 8, rails of track 21,resistance 9, contact 77 and contact 62 to the secondary of transformerB The contacts 61 and 62 of circuit controller Z constitute apolechanger so that the relative polarity of the 100 current thussupplied to the track a s is periodically reversed. Consequently, when atrain moving toward the left approaches signal A all three relays W, X

' and (see Fig. 2) will be energized, so that the mdication given aboardthe train will Proceed at slow speed.

I will now assume that switch M is re- N is normal, and that s gnal A ismoved to. theproceed position. Track circuit current will then besupplied to the rails of track immediately to the right of point K,suchcurrent flowing from the secondary of transformer 16, through contacts66 and contacts 79 and 80.

The normal loop circuit for track 90 is nov open at contacts 81 and 82,but loop curren is supplied from transformer B througl contacts 61 and62, and through contacts 81 and 82 to resistances 8 and 9 in track 90.I1 follows that a train moving toward the lef and approaching signal Awill receive tlu indication Proceed at slow speed.

If switches M and N are both reversed and signal A is moved to theproceed osition, track circuit current will be supplied to the rails oftrack89 immediately to the right of point H, the circuit being fromtransformer 16, through contacts 66 and contacts 84 and 85. Loop currentis supplied to track 89 from the secondary of transformer B throughcontacts 61 and 62 of circuit controller Z and contacts 86 and 87operated by signal A A train moving toward the left and approachingsignal A will, therefore, receive the indication Proceed at slow speed.

Referring again to Fig. 2, it will be seen that if relay J isde-energized and immediately energized, lamp U will be lighted for abrief interval of time. This is because relay W becomes energized whencontact 32 closes, so that when contact finger 31 swings to the right,relay X will become energized. This momentary lighting of lamp U mayoccur, for example, when the train passes from onetrack circuit toanother under proceed indications. Similarly, when passing from onetrack circuit to another under caution indications, lamp T may belighted for a brief interval of time. To prevent these brief indicationsbeing given by lamps U and T, the apparatus shown in Fig. 3 may be used.In this view lamps G, Y and R are controlled by contact 30 of relay J inthe same manner as in Fig. 2. An additional slow-releasing relay V isprovided, however, which relay can be energized onl when re lay X orrelay-Q, is energized and back contact 32 of relay J is closed. Assumingthen that relay J is energized in normal direction and momentarilybecomes de-energized, the closing of back contact 32 will energize relayW, and when contact 31 again becomes closed relay X will be energized.Relay V will not be energized, however, because back contact 32 of relayJ remains open, consequently relays W and X will open at the exirationof the time intervals and the signal amps U, T and S will not beaffected. If,

however, relay J is intermittently energized in the normal direction,relay W will become energized the first time that back contact 32 coses, relay X will become closed upon the subsequent closing of contact31, and the second time that contact 32 closes relay V will becomeenergized by virtue of a circuit which passes from the terminal of asuitable source of current, through contact 32 of relay J and contact 37of relay X. The 1 neaaeae result will be that relays W, X and V are allclosed, so that the circuit for lamp U will then pass from the terminalof a suitable source of current, through contact 36 of relay TV, contact41 of relay V, contact 102 of relay X, and back contact 39 of relay Q,to lamp U. If relay J is intermittently energized in reverse direction,relays W, Q and Vwill be energized, whereupon the circuit for lamp T isfrom the terminal, through contact 36, contact 41, and contact 38 tolamp T. If relay J is intermittently energized in opposite directions,all four relays W, X, Q and V will be energized, so that lamp S will belighted by virtue of a circuit which passes from the terminal of thesource of current, through contact 36, contact 41, contact 102 and thefront point of contact 39 to lamp S.

Tteferring now to Fig. 4c, the apparatus here shown is similar to thatshown in Fig. 2, except that the single line relay J of Fig. 2 isreplaced by two relays J and J B in Fig. 4. When these relays aresupplied with track circuit current of normal relative polarity and loopcurrent of normal relative polarity, the contacts of relay J B arepicked up but the contacts of relay J are not picked up. When the relaysare supplied with track circuit current and loop current the relativepolarity of one of which is reversed, the contacts of relay J are pickedup but the contacts of relay J are not picked up. When the supply ofeither track circuit current or loop current is discontinued, bothoftheserelays are de-energized. The proceed lamp G is supplied withcurrent through contact 43 of relay J, the cau tion lamp Y is suppliedwith current through contact 42 of relay J and the stop lamp R issupplied with current through back contacts 44 and 45 of relays J A andJ respectively. The operation of the apparatus in so far as these threelamps are concerned will be understood without further explanation. Thecircuit for relay W includes back contact 32 of relay J A and backcontact 32 of relay J so that relay W is energized only when both relaysJ and J are open. The circuit for relay X includes contact 36 of, relayTV and contact 31 of relay J so that relay X can be energized only whenrelay W and relay J are both energized. Similarly, the circuit for relayQ includes contact 36 of relay W and contact 31 of relay J. so thatrelay Q can be energized only when relays W and J are energized. LampsU, T and S are controlled by relays \V, X and Q in the same manner as inFig. 2. It will lee-apparent, therefore, that when the train receivestrack circuit current of normal relative polarity and intermittent loopcurrent of normal relative polarity, lamp U will be lighted; when thetrain receives track circuit current of reverse relative polarit andintermittent loop current, lamp T will be lighted; and when the trainreceives track circuit current and also loop current periodicallyreversed in relative polarity, lamp S will be lighted.

It will, of course, be. apparent that the apparatus shown in Fig. 4 maybe modified by the addition of relay V as in Fig. 3, if desired.

As herein shown the relay J (and relays J and J together with theapparatus controlled thereby are carried on a train, but it isunderstood that this specific location of such relays and apparatus isnot essential to my invention.

Although I have herein shown and described only a few forms of apparatusembodying my invention, it is understood that various changes andmodifications may be 4 made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traffic controlling apparatus comprising means for supplyingtwo alternating currents to the trackway and for at times interruptingone of said current-s periodically, and train-carried mechanism con- 4trolled lay-said currents and arranged to give one indication when bothcurrents are continuously supplied and a different indication when onecurrent is continuously supplied and the other is periodicallyinterrupted.

2. Railway trafiic controlling apparatus comprising means for supplyingthe track- Way with two alternating currents of the same frequency butdifiering in phase. means controlled by traflic conditions for at timesinterrupting one of said currents periodically and for at other timesperiodically reversing the relative phase of one of said currents, andtrain-carried governing mechanism controlled by said currents.

3. Railway trafiic controlling apparatus comprising means for supplyingtwo alternating currents to the trackway and for at times interruptingone of said currents periodically, and train-carried mechanismcontrolled jointly by said two currents and responsive to suchperiodicinterruption of said one current.

4. Railway traffic controlling'apparatus comprising means for supplyingthe trackway with two alternating currents of, the

same frequency but differing in phase, means controlled by trafficconditions for at times interrupting one of said currents periodicallyand for at other times periodically recurrent is periodicallyinterrupted or the relative phase of one current is periodicallyreversed.

5. Railway traffic controlling apparatus comprising means for supplyingthe trackway with two alternating currents having one phase relation oranother and for periodically interrupting one of said currents, andtrain-carried mechanism controlled jointly by said currents and arrangedto give different indications according as said currents bear one phaserelation or the other.

6. Railway trafiic controlling apparatus comprising means for supplyingthe trackway with two alternating currents having one phase relation oranother and for at times periodically interrupting one of said currents,and train-carried mechanism controlled by said currents and arranged togive two different indications when both currents are suppliedcontinuously according as said currents have one phase relation oranother and to give two other distinctive 1ndications when one currentis periodically interrupted according as the currents have one phaserelation or the other.

7. Railway traflic controlling apparatus comprising means for supplyingthe track- Way with two alternating currents having one phase relationor the other, means for at times periodically interrupting one of saidcurrents and-for at other times periodically reversing the phase of onecurrent with respect to the phase of the other, and traincarriedmechanism-controlled by said currents and arranged to give twodistinctive indications when both currents are supplied continuouslyaccording as said currents have one phase relation or the other and togive two other distinctive indications when one current is periodicallyinterru ted according as the currents have one p iase relation or theother and to give a fifth distinctive indication when the phase of onecurrent is periodically reversed with respect to the other.

8. Railway trafi'ic controlling apparatus comprising means for supplyingtwo alternating currents to the trackway and for at times periodicallyreversing the phase of one current with relation to the phase of theother, and train-carried mechanism controlled jointly by said currentsand responsive to such periodic reversal of the relative phase of onecurrent.

9. Railway traific controlling apparatus comprising means for supplyingtwo alternating currents to the trackway and for at times periodicallyreversing the phase of one current with relation to the phase of theother, and train-carried mechanism controlled jointly by said currentsand arranged to give one indication or another according as the phaserelation of the currents is maintained constant or the relative dphaseof one current is periodically reverse 10. Railway traflic controllingapparatus comprising means for supplying two alternating currents to thetrackway and for at times interrupting one of said currentsperiodically, train-carried mechanism controlled by said currents andincluding two contacts, means for closing the first contact when saidtwo currents are supplied continuously and for alternately closing thefirst and second contacts when one current is supplied continuously andthe other is periodically interrupted, a slow releasing relay on thetrain energized when said second contact is closed, a second slowreleasing relay on the train energized when said first contact is closedand said first relay is closed, each of said relays being arranged toremain closed continuously during periodic interruption of one of saidcontacts, and governing means on the train controlled by said two slowreleasing relays.

11. Railway traific controlling apparatus comprising means for supplyingtwo alternating currents to the trackway and for at times interruptingone of said currents periodically, train carried mechanism controlled bysaid currents and including two contacts, means for closing the firstcontact when said two currents are supplied continuously and foralternately closing the first and second contacts when one current issupplied continuously and the other is periodically interrupted, aslowreleasing relay on the train, a circuit for said relay including thesecond of said contacts, a second slow releasing relay on the train, acircuit for said second relay including the first of said contacts and afront contact of said first relay, and governing means on the traincontrolled by said second slow releasing relay.

12. Railway trafliic controlling apparatus comprising means forsupplying the trackway with two alternating currents having one phaserelation or the other, means for at times periodically interrupting oneof said currents and for at other times periodically reversing the phaseof one current with respect to the phase of the other, three slowreleasing relays carried on a train, means for energizing the first ofsaid relays when either of said currents is interrupted, means forenergizin the second or third of said relays when t e first relay isclosed and both of said currents are present according as they have onephase relation or the other and for energizing bothof said relays whenthe phase of one current is periodically reversed with respect to thephase of the other, and governing mechanism on the train controlled bysaid second and third relays.

13. Railway trafiic controlling apparatus comprising means for supplyingthe trackway with two alternating currents having one phase relation orthe other, means for at times periodically interrupting one of saidcurrents and for at other times periodically reversing the phase of onecurrent with respect to the phase of the other, three slow releasingrelays carried on a train, means for energizing the first of said relayswhen either of said currents is interrupted, means for energizing thesecond or third of said relays when the first relay is closed and bothof said currents are present according as they have one phase relationor the other and for energizing both of said relays when the phase ofone current is periodically reversed with respect to the phase of theother, and governing mechanism on the train arranged to give oneindication or another according as the second or third relay isenergized and a third indication when boththe second and third relaysare energized.

14. Railway traflic cont-rolling apparatus comprising means forsupplying the trackway with two alternating current-s having one phaserelation or another and for at times periodically interrupting one ofsaid currents, a relay on a train, means for energizing said relay inone direction or the other when said two currents are present ac cordingas the currents have one phase rela tion or the other and fortie-energizing said relay periodically when one current is pe riodicallyinterrupted, and governing mechanism on the train controlled by saidrelay. '15. Railway traflic controlling apparatus comprising means forsupplying the trackway with two alternating currents having one phaserelation or another and for periodically interrupting one of saidcurrents, three slow releasing relays carried on a train, means forclosing the first rela whenever one of said trackway currents isinterrupted,

means for closing the second or the third re-' lay when the first relayis closed and both currents are present according as said cur-. rentshave one phase relation or the other, and governin mechanism on thetrain controlled by sai relays.

16, Railway traific controlling apparatus comprising means for supplyingthe trackway with two alternating currents having one phase relation oranother and for pcriodically interrupting one of said currents, threeslow releasing relays carried on a train, means for closing the firstrelay whenever one of said trackway currents is interrupted, means forclosing the second or the third relay when the first relay is closed andboth currents are present according as said currents have one phaserelation or the other, a fourth slow releasing relay on the train, meansfor closing said fourth relay when either the second or the third relayis closed and the supply or one of said trackway cur rents isinterrupted, and governing mechanism on the train controlled by saidrelays,

17. Railway trafic controlling apparatus comprising means for supplyingthe trackway with two alternating currents of the same frequency butdiffering in phase, means controlled by trafic conditions in advance forat times reversing the relative polarity of one of said currents, meansalso controlled by traific conditions in advance for at timesperiodically interrupting one of said currents and for at timesperiodically reversing the relative polarity of one of said currents,and train-carried governing means controlled jointly by said twocurrents and responsive to the relative polarity of such currents and tothe periodic interruption and reversal thereof.

ture.

HERBERT A. WALLACE.

